These are likely future disc releases from the Criterion Collection. In order of likelihood, starting with almost certain and ending with substantially rumored.
Note: this does not include upgrades - for that list, see the Don't Buy list below.
Heard about something not included here? Leave a comment below.
Other lists in this guide:
An Introductory Guide
100 Films to Watch on the Criterion Channel
DVD-only Titles Worth Buying
Titles To Wait On Upgrades
Better Non-Criterion Editions
In-Print DVD-Only Criterion Titles
Ten Must-See Eclipse Titles